Automatic reclosing circuit-breaker system



July 10, 1928. 1,676,315

A. E. ANDERSON AUTOMATIC RECLOSING CIRCUIT BREAKER SYSTEM Original Filed Oct. 5, 1925 2 Sheets-Sheet 1 InvenLcW":

H as Atnorwel July 10, 1928. 1,676,315

A. E. ANDERSON AUTOMATIC RECLOSING CIRCUIT BREAKER SYSTEM Original Filed Oct. 5, 1925 2 Sheets-Sheet 2 Inventor: Ar\/id EAn-derson;

His Anborneg- Patented July 10, 1928.

UNITED STATES rA'rEu'r OFFICE.

ABVID E. ANDERSON, OF SCHENECTADY, NEW YORK, ASSIGNOR T0 GENERAL ELECIBIG COMPANY, A CORPORATION OF NEW YORK.

AUTOMATIC BECLOBING CIRCUIT-BREAKER SYSTEH.

Application filed October 3, 1923, Serial No. 886,421. Renewed May 26; 1888.

My invention relates to automatic reclosing circuit breaker systems and is particu-' larly applicable to the type of automatic reclosing circuit breaker system used to con- 5 noct together two electric circuits both of which, at certain times, are independently energized and only one of which, at other times is independently energized. One object of my invention is to provide an 1mproved automatic reclosing circuit breaker system of this 12 pe which will operateto close the circuit breaker, which is arranged to connect the circuits together, when either one or both of the circuits are energized.

My invention will. be better understood from the following description taken in connection with the accompanying drawings and its $00 'e will be pointed out in the appended clauns.

In the accompanying drawings, Fig. 1 shows diagrammatically one embodiment-of my invention for connecting together two circuits which have a common return, Fig. 2 is a modification of the arran ement shown in Fig. 1, Fig.3 is a modification of the arrangement shown in Fig. 2, Fig. 4 is a modification of the arrangement shown in Fig. 2, the two circuits being provided with independent return circuits, and 5 and 6 show modifications of the arrangement shown in Fig. 4. c

Referring to Fig. 1, 1 and 2 represent respectively conductors of two circuits which are arranged to be connected together by a circuit breaker 3 which may be of any suitable type. The conductors 1 and 2 may for example be considered as the supply c0nductors of two sections A and B of a trolley circuit of a railway system in which the return circuit of the two sections is through ground. It is apparent, however, that it is immaterial whether a grounded returner a metallic return is used. The sections A and B are assumed to be energized independent 7 .1y from a suitable source or sources not shown, in a manner well known in the art.

Any suitable means may .be used force-los the circuit breaker 3'and in the drawing ill I have shown a closing coil for this' purpo'e. This closing coil 4, when energized, closes the circuit breaker and holds it closed as long as the voltage supplied thereto is above a predetermined value.

It is apparent that if the sections A and B are always supplied with current at noris arranged to be energized only when the lnal voltage, the closing coil 4 of the circuit breaker 3 can always be connected to the same section whenever it is desirable to close the circuit breaker automatically.' Since, however, conditions may occur whereby the source which normally supplies current to one section may fail, whereas the other tlon may be energized, it is apparent that if the closinge coil of the circuit breaker is arranged to connected always to the same cs section, the circuit breaker can be closed automatically only'when the section, to which the closing coil is arranged to be connected, lsenergized. According to my invention I control the circuit of the closing coil, of the circuit breaker so that it is energized .from y .the energized circuit when either one or both i of the two circuits, to which it is arranged to be connected automatically, isenergized. Therefore in the arrangement shown, in which the sections A and B are the two circuits to which the closing coil is arranged to be connected, it is apparent that as long as either section A or B is energized, the circuit breaker 3 may be reclosed automatically.

In order to energize the closing coil 4 from the section which is energized when only one section isfenergized, I provide two voltage relays'fi and 6 which control the connections bet een. the closing coil 4' and the sections A and B. The coil of the voltage relay 5 is connected across the section A and is arranged,-when energized, to connect the closing coil 4 directly across section A. The coil 0 the voltage relay 6 is arranged to be connected across the section Bwhen'the voltage relay 5 is deenergized. The relay 6, when energized, connects the closing coil 4 across section B. Since the voltage relay 6 c5 voltage relay 5 is deenergized, it is ap aren't that when either section is energize and the circuit'breaker 3 is closed, the voltage relay 5 is energized and therefore the circuit for the voltage relay 6 and the circuit 100 of the closing coil 4 controlled thereby are pen. .4 1 f 11 order that the conductors 1 and 2 may not be connected directly together through the'contacts of the voltage relays 5 and 6, 105 either when both of the sections are enerized at the same instant when the circuit reaker is open, in which case both of the ,voltage relays may be simultaneously operated, or when the circuit breaker 3 is closed no due to the energization of section B and the voltage relay connects the closing coil 4: to section A before the voltage relay 6 can open its contacts and disconnect the closing the contacts of the voltage relays.

coil 4 from section B, a current limiting device such as a relatively high resistor 7 is connected in the circuit of the closing coil 4 controlled by the voltage relay 5 and another current'limiting device such as a relatively high resistor 8 is'connected in the circuit of the closing coil 4 controlled by the voltage relay 6. Therefore when both of the voltage relays 5 and 6 are in-their energized positions, the resistors 7 and 8 are connected in series between the conductors 1 and 2 so that only a very small current can flow through While I have shown two resistors 7 and 8 it is apparent that the same result may be obtained by omitting either one of the resistors and dcsigningthe other resistor so as to limit the current through it under the above mentioned conditions to a'predeterrnined value.

' I prefer, however, to use two resistors which have substantially the same value of resist= ance so that the closing coil 4 will have sub stantially the same vo tags impressed there on when either section is energized.

In order that the circuit breaker ma be opened when an excessive current flows rom one section to the other, an overload relay 10 is provided which is connected in the cir cuit between sections A and B when the cir-' cuit breaker 3 is closed and which is arranged to open the circuit of the closing coil 4. The overload relay is pot '11, so that it does not close its contacts 13 in the closing coil circuit until a redetermined time after the circuit brea er 3 opens due to the operation of the overload relay 10.

contacts, the circuit breaker is reclosed if either one of the sections is energized. this manner when there is an overload connected to one section and the other section is energized, the circuit breaker is automatically recloscd periodically until the overload '7 Fig. 1 is as follows is removed or further reclosing is prevented by opening the circuit of the closing coil in an well known manner, not shown.

e operation of the system shown in :Let it be assumed-that the circuit breaker 3 is 0 an and only the section A is energized. V0 tags relay 5 then becomes energized and, by c osing its con: tactS12', completes a circuit from the sup. ply conductor 1 of section A through contacts 12 of relay 5, resistor 7, contacts 13 of the overload relay 10, closing coil 4 of the circuit breaker. 3 to ground which is the re turn circuit of section A. The ener ation of the-closing coil 4 closes the circuit @eaker 3 which in turn connects section B to section A so that section B is energized. Since the arranged in any suitable'ma'nner as by means of a dash When theoverload relay closes its circuit of the voltage relay 6, which is arranged to be connected across section B, is open at the contacts 15 of the voltage relay 5, the voltage relay 6 is not energized when the circuit breaker closes.

I Let it now be assumed that. the circuit breaker 3 is open and only the section B is energized. The circuit for the voltage relay 6 isthen completed, this circuit being from the supply conductor 2 of section B, through the Coll of the voltage relay 6, contacts 15 of the voltage relay 5 to ground which is the return circuit of section B. The closing of the contacts 16 of the voltage relay 6 completes a circuit .from the supply conductor 2 of the section B, through contacts 16 of the rela 6, resistor 8, contacts 13 of the overloa relay 10, closing coil 4 of the circuit breaker 3 to ground. The energization of the closim coil closes the circuit breaker 3 so that the section 1 is energized. Voltage relay 5 then becomes energized and completes the above traced circuit for the closing coil 4 between the supply conductor 1 of section 'A and ground. The voltage relay 5 by opening its contacts 15 opens the circuit of the voltage relay 6 which in turn opens the circuit of the closing coil 4 controlled the resistors -7 and 8 are ing from one section to the other throughthe, I

contacts 12 and 16 of the voltagerelays 5 and 6 respectively under this condition. As soon as the, voltage role. 6 opens its contacts 16 only the closing coi circuit through the contacts 12 of the voltage-relay .6 remains I completed.

It is apparent that if both sections are ener 'zed simultaneously :when the circuit brea er 3 is open, both oithecircuits of the closingcoil 4 are completed for an instant. The opening of the contacts 15 of the relay 5 however, deenergizee: relay 6 so that-closing coil'circuit through the contacts 16 0f the relay 6 is opened. Afterfthe; circuit breaker is closed it remains closed aslon" as either section is independently energized and the current through the circuit breaker does not. exceed a predetermined value. It is obvious that if the voltage {across both sections drops below a predetermined value, the voltage relay 5 opens the circuit of the closing coil 4 and the circuit breaker opens andre'mains open until the voltage on one of thESGOtlODS increases above a predetermined voltage determined by the setting of the the current through the circuit breaker exceeds a predetermined value the overload relay 10 opens its contacts 13 and deenergizes the closing coil 4 of "the circuit"breaker-3 so that the circuit breaker opens. After a predetermined time determined by the setting of the dash pot 11, the overload relay 10 again closes its contacts 13 and the closing coil 4 is connected across the energized section in the manner heretofore described. If the abnormal condition is still connected to the system when the circuit breaker '3 recloses, the overload relay operates again and the above cycle of operation is repeated, until either the abnormal condition is remo ed or the circuit of the closing coil 4 is opened in any well known manner, not shown.

In the modification of my invention shown in Fig. 2, the overload relay 10 controls the closing coil 20 of a second circuit breaker 21 which when opened, inserts a current limiting device 22, shown as a resistor, in series between the two sections A and B so as to limit the flow of current from one section to the other when an abnormal condition occurs on one section and the other section is energized. The circuit of the closing coll 20 is arranged to be completed by means of the auxiliary contacts 23 on. the circuit breaker 3 which are closed only when the circuit breaker 3 is closed. Therefore the circuit breaker 21 canbe closed only after the circuit breaker 3 is closed. The closing coil 20 may be connected across one of the sections such as section A as shown in Fig. 2,

since both sections are energized after the closing of the circuit breaker 3 or it may be connected to either section by the relays 5 and 6 in the same way that the closin coil 4 is connected to either section. This re- ,sult may bev obtained, for example, by connectin the coil 20 in parallel with the dos ing coil 4 of the circuit breaker 3 in the manner shown in Fig. 3.

The overload relay 10 and the resistor 22 are so designed that when the circuit breaker- 21 is open, sufficient current is supplied to the section to which the abnormal condition is connected to maintain the contact 13 of theoverload relay open as long as the abnormal condition remains connected to the.

section: In order to prevent'the resistor 22 from overheatingwhen the circuit breaker 21 is open, a thermostat 25 is placed near the resistor so as to be affected by the temperature thereof. This thermostat is arranged to effect the opening of the circuit breaker 3 so as to disconnect the two sections A and B from each other when the temperature of the resistor 22 exceeds a predetermined value I and to maintain said circuit breaker open until the temperature of the resistor decreases below a predetermined value. As shown in Fig. 2this result is obtained by having the thermostat open the contacts 26 in the circuit of the voltage relay 5 and close the contacts 27 in shunt around the coil of the voltage relay 6 when the temperature ofthe resistor exceeds a predetermined value. As shown in Fig. 3 this result is obtained by having the thermostat open the contacts 26 and 28 in the circuits of the voltage relays 5 and 6 respectively.

In order to prevent a short circuit being maintained across the section B in Fig. 2 when the contacts 27 of the thermostat are closed, a high resistance 29 is provided in series with the coil of the voltage relay 6 so that it is in series withthe contacts 27 when they are closed.

The operation of the modifications shown in Figs. 2 and 3 so far as the arrangement for connecting the closing soil 4 to an energized section, is the same as in Fig. 1 so that a. description thereof is deemed unnecessary. In Fig. 2 when the circuit breakers 3 and 21 are closed and an excessive current flows from one section to the other, the overload relay 10 opens its contacts 13 and the circuit breaker 21 opens. As long as an abnormal condition remains connected to one section and the other section is energized, suh'icient current flows through the resistor 22 to maintain the contacts 13 of the overload relay 10 open. If the resistor 22 overheats,.the thermostat 25 opens contacts 26 and closes contacts 27 so that the circuit of the voltage relay 5 is opened and the coil of the voltage relay 6 is short circuited. Consequently both of the voltage relays are deenergized and the circuit breaker 4 opens. As soon as the resistor 22 cools and the thermostat 25 opens contacts 27 and closes contacts 26, the circuit breaker 3 is reclosed in a manner heretofore described.

If there is no overload connected to either section when the circuit breaker 3 closes, the current through the overload relay 10 is not suiiicient to operate the relay and. therefore the closing of the auxiliary contacts 23 of the circuit breaker 3 connects the closing coil 20 of the circuit breaker 21 across section A. The closing of the circuit breaker 20 again connects section A directly to section 3.

If when the circuit breaker 3 closes, there is a short circuit or overload connected to either section, the overload relay operates and prevents the circuit breaker form closing until the load conditions are normal.

The operation of the modification shown in Fig. 3 is the same as Fig. 2 except that the opening of the contacts 26 and 28 of the thermostat opens the circuit of both of the voltage relays 5 and 6 and, theclosing coil 20 is arranged to be connected in parallel with the closing coil' 4 instead of always becircuit, which may be ground,'and the circuit breaker 3 only opens the connection between the supply conductors 1 and 2. Therefore in such systems one terminal of the closing coil 4 can be connected directly to the common circuit and the voltage. relays 5 and 6 have to control the connection of only one terminal of the closing coil 4 in order to connect the coil across the, respective sections when the circuit breaker is open.

When, however, it is necessary to open the connection between both conductors of the two sections when they are disconnected from each other, the voltage relays have to be arranged to connect both terminals of the closing coil to the conductors of the respec tive sections. In Fig. 4, which is a modification of the arrangement shown in Fig. 2, the return circuit instead of being the ground, consists of conductor 31 for section A and conductor 32 for section B. The circuit breaker 3, when closed respectively connects conductors 1 and 31 of section A to conductors 2 and 32 ot' section B.

The closing coil 4 of the circuit breaker 3 is arranged to be connected across section A through the contacts of the voltage relay 5 and is arranged to be connected across section B through the contacts of the voltage relay 6. The contacts 12 of the voltage relay 5 are arranged to connect one terminal of the closing coil 3 to conductor 1 of section A and contacts 16 of the voltage relay 6 are arranged to connect the same terminal of the closing coil 3 to conductor 2 of section B in the same manner as in Fig. 2. The other terminal of the closing coil 4 however. is arranged to be connected to conductor 31 of section A by contacts 33 of relay 5 and to conductor 32 of section B by contacts 34 of relay 6. As mentioned above the resistors '2' and 8 are connected in series between the closing coil 4 and the conductors 1 and 2 respectively so as to limit the current through the contacts 12 and 16 of the relays 5 and 6 respectively in case both of these contacts are closed at the same time. Forthe same reason the resistors 35 and 36 are connected in series between the closing coil 4and the conductors 31 and 32 respectively so as to limit the current through contacts 33 and 34 when both of these contacts are closed at the same instant.

The voltage relays 5 and 6 are respectively connected between the conductors of sections A and B in the same manner as shown in Fig. 2 except that instead of being connected directly to the return conductors of the re- 'spective sections a current limiting device is connected in series therewith. As shown in Fig. 4 a resistor 38 is connected in series between the conductor 31 of section A and the coil of the voltage relay 5, and a resistor 39 is connected in series between the conductor 32 of section B and the coil of the voltage relay 6. These two resistors are so connected in the respective circuits that when the circuit breaker 3 is open they are connected in series between conductors 31 and 32 and therefore limit the amount of current that can flow from one conductor to the other when the circuit breaker 3 is open. Resistors 29, 38 and 39, and coils of relays 5 and 6 are preferably selected so that both relays operate in response to substantially the same voltages- Since the operation of the arrangement shown in Fig. 4 is the same as the arrange- 'ment shown in Fig. 2, a description thereof is believed to be unnecessary.

The arrangement shown in Fig. 5 is the same as the arrangement shown in Fig. 4 .except that the circuit breaker 3 is replaced by two circuit breakers 3 and 3 the resistors 8. 35, 38 and 39 have been omitted and the thermostat 25 connects the voltage relays 5 and 6 across the sections A and B in the manner shown in Fig. 3.

The circuit breaker 3 is arranged to connect the conductors 1 and 2 together and the circuit breaker 3 is arranged to connect the conductors 31 and 32 together. The closing coils 4 and 4 are connected in series with each other, and the circuit of these coils is completed by the voltage relays 5 and 6 in the same way as shown in Fig. 4. It will be observed that in case the contacts 12 and 16 and the contacts 33 and 34 of the voltage relays 5 and 6 are closed at the same instant the resistor 17 will limit the currentflowing between conductors 1 and 2 through contacts 12 and 16 and resistor 36 will limit the cur rent flowing between conductors 31 and 32 through contacts 33 and 34.

By arranging the circuits of the voltage relays 5 and 6 so that separate contacts of the thermostat 25 connect the relays across the respective sections. the resistors 38 and 39 may be omitted since the circuits of these two relays are entirely independent of each other.

In the modification of Fig. 5 shown in Fig. 6. the voltagerelay 6 is omitted and the closing coils 4 and 4 are arranged to be connected across section B by contacts of the voltage relay 5 when section A is not energized, the closing coils 4 and 4 being arranged so that they close when the voltage impressed thereon exceeds a prcdetern'lined value. The contacts 16 of the voltage relay 6 in Fig. 5 are replaced by the contacts 40 of the relay 5 which are closed when the relay 5 is deenergized and the contacts 34 of the relay 6 are replaced by the contacts 41 of the relay 5. The contacts 28 of the thermostat are connected in the circuit of the closing coils 4* and 4 which is arranged to be connected across section B.

It will be observed that when the circuit contacts 40 of the voltage relay 5, closing coil 4 closing coil 4*, resistor 36, contacts 41 of the voltage relay 5, contacts28 of the thermostat 25 to the conductor 32 of section B. Therefore if section B is energized, the circuit breakers 3 and 3 close and relay 5 becomes energized so that the above traced circuit is opened at contacts and 41 of the relay 5. The relay 5 is arranged,

however, so that it closes its contacts 12 and 33 before it opens its contacts 40 and 41. Therefore a circuit is completed from conductor 1 of section A through contacts 12 of the voltage relay 5, resistor 7 closin coil 4, closing coil 4, contacts 33 of re ay 5 to the conductor 31 of section A to maintain the closing coils 4 and 4 energized after the contacts 40 and 41 are opened. During the time the contacts 12 and 40 are simultaneously closed the resistor 7 limits the current flowing between conductors 1 and 2 through these contacts and durin the time the contacts 33 and 41 are simu taneously closed the resistor 36 limits the current flowing between conductors 31 and 32.

It is believed that the rest of the operation of the arrangement shown in Fig. 6 is obvious from the description heretofore given of the other arrangements;

While I have shown and described several embodiments of my invention, I do not desire to be limited thereto but seek to cover in the appended claims ,all those embodiments and modifications thereof that fall within the true spirit and scope of myin vention.

What I claim as new and desire to secure by Letters Patent of the United States, is,-

1. In an automatic reclosing .circuit breaker system, two electric circuits ada ted to be ener ized independently of each ot er, a circuit breaker arranged to connect said circuits together, a'closing coil for said circuit breaker, means responsive to a predetermined. voltage across one of said electric circuits for completing an energizing circuit for said closing coil across said one of said electric circuits, another ener izin for said closing coil arrange to e completed across the other of said electric circuits, and a current limiting device in one of the circuits of said closing coil arranged to be connected in a shunt circuit around said circuit breaker to limit the flow of current between said electric circuits only when both of said energizing circuits are simultaneously completed.

2. In an automatic reclosing circuit breaker system, two electric circuits adapted to be ener ized independently of each other, a circuit reaker arranged to connect said circuits together, a closing coil for said circircuit cuit breaker, means responsive to a predetermined voltage across one ,of said electric circuits for completing an energizing circuit for said closing coil across said one of said electric'circuits, means responsive to a predetermined voltage across the other of said electric circuits for completing an energizing circuit for said closing coil across said other of said electric circuits, and a current limiting device in one of said energizing circuits arranged to be connected in a shunt circuit around said circuit breaker to limitthe flow of current between said electric circuits only when both of said voltage responsive devices are simultaneously energized.

3. In an automatic reclosing circuit breaker system, two electric circuits adapted to be energized independently of each other, circuit interrupting means arranged to connect said electric circuits together, electroresponsive means for closing said circuit interrupting means, a current limiting device, means responsive to the voltage across one of said electric circuits for connecting said electroresponsive means and said current limiting device in series across said one of said electric circuits, a second current limit-' ing device, and means responsive to the voltage across the other one of said electric circuits only when said circuit interrupting means is open for connecting said electro responsive means and said second current limiting device across said last mentioned electric circuit, said current limiting devices being so connected that only when both of said voltage responsive means are simultaneously energized said devices are connected in series with said electric circuits.

4. In an automatic reclosing circuit breaker system, two electric circuits adapted to be energized independently of each other, a circuit breaker arranged to connect said circuits together, a closing coil for said circuit breaker, a circuit for said closin coil arranged to be completed across one 0 said electric circuits when said one of said electric circuits is energized, a relay responsive to the voltage across said one of said circuits for controlling the circuit of said closing coil, another circuit for said closing coil arranged to be completed across the other one of said electric circuits, and means controlled by said relay for preventing the completion to the voltage across said one of said electric circuits for controlling the circuit of said closing coil, another circuit for said closin coil arranged to be connected across a the ot or one of said electric circuits, a voltage relay responsive to the voltage across said other one'of said electric circuits for controlling said last mentioned circuit for said closing coil, and means controlled by said first mentioned voltage relay for preventing the completion of said last mentioned circuit for said closingcoil after said. first mentioned voltage relay has operated to complete the first mentioned circuit :Ecrv 1."; said closing coil.

6. In an automatic -reclosing circuit breaker system, two electric circuits adapted to be energized independently of each other, a circuit breaker arranged to connect said circuits together, a closing coil for said circuit breaker, a circuit for said closing coil arranged to be'completed across one of said electric circuits, contacts in said closing coi circuit, a voltage relay responsive to a preill l eietermined voltage across said one of saidelectric circuits for closing the contacts in said closing coil circuit, another circuit for said closing coil arranged'to be connected across the other one of said electric circuits, so contacts in said last mentioned closing coil circuit, a voltage relay responsive to a predetermined voltage across said other one of said circuits for closing said contacts in said last mentioned closing coil circuit, and cones tacts in the circuit of said last mentioned volta e relay controlled b said first mentioned voltage relay where y said last men tioned voltage relay can be energised only when said first mentioned voltage relay is o deenergized.

7. In an automatic reclosing circuit breaker system, two electric circuits ada ted to be ener ized independently at each ot er, a circuit reaker arranged to connect said circuits together, a closing coil for said circuit breaker, a circuit for said closin coil arranged to be completed across one 0 said electric circuits, a resistor in said circuit of said closing coil, contacts in said circuit oi so said closing coil, a voltage relay responsive to a predetermined voltage across said one of said electric circuits for closing thecontacts inthe circuit of said closing coil, another circuit for said closing coil arran ed to as be completed across the other one 0% said electric circuits,-a resistor in said last mentioned closing coil circuit, contacts in said last mentioned closing coil circuit, a voltage relay responsive to a predetermined voltage to across said other one of said electric circults for closing said last mentioned closing coil circuit, and contacts in the c rcuit of said last mentioned voltage relay controlled by said first mentioned voltage relay whereby said as last mentioned voltage relay can be enerbreaker system, two electric circuits adapted to be energized independently of each other,

a current limiting device, an overload relay, a circuit breaker arranged to connect said current limiting device and said overload relay in series between said circuits, a second circuit breaker arranged to short circuit said current limiting means, an operating coil for said second circuit-breaker controlled by overload relay and said iirst mentioned circuit breaker, an operating coil for said first mentioned circuit breaker, and voltage responsive means for selectively connecting the operating coilfor said first mentioned circuit breaker across the electric circuit which is energized when one of said electric circuits is energized 9. In an automatic reclosing circuit breaker system, two electric circuits adapted to be energized independently of each other,

a current limiting resistor, an overload relay, a circuit breaker arranged to connect said resistor and said overload relay in series between said circuits, a second circuit breaker arranged to short circuit said current limiting means, a closing coil for said second circuit breaker, a circuit for said closing coil arranged to be completed when said first mentioned circuit breaker is closed and the current through said. overload relay is less than a predetermined value, a closing coil for saidfirst mentioned circuit breaker, a circuit for the closing coil or said first mentioned circuit breaker arranged to be completed across one of said electric circuits, a relay responsive to the voltage across said one of said electric circuits for controlling said circuit of the closing coil of the first mentioned circuit breaker, another circuit for the closing coil oil the first mentioned circuit breaker arranged to be completed across the other electric circuit when said relay is deenergized, and means responsive to the temperature of said current limiting resistor for controlling both of the circuits of the closing coil of said first mentioned circuit breaker. I

10. In anflautomatic reclosing circuit breaker system, two electric circuits adapted to be energized independently of each other, a current limiting resistor, an overload relay, a circuit breaker arranged to connect said resistor and said overload relay in series between said circuits, a second circuit breakor arranged to short circuitsaid current limiting means, a closing coil for said second circuit breaker, a circuit for said closing coil ar ranged to be completed when said first mentioned circuit breaker is closed and the current through said overload relay is less than a predetermined value, a closing coil for said first mentioned circuit breaker, means responsive to the voltage across one of said electric circuits for connecting the closing coil for said first mentioned circuit breaker across said one of said electric circuits when said one of said electric circuits is energized, means responsive to the voltage across the other one of said electric circuits for connectingthe closing coil for said first mentioned circuit breaker across said other one of said electric circuits when only said other one of said circuits is energized, and means responsive to the temperature of said current limiting resistor for rendering both of said voltage responsive means inoperative to close the circuit of the closing coil of said first mentioned circuit breaker when the temperature of said resistor exceeds a predetermined value.

11. In an automatic rcclosing circuit breaker system in which two sections of an electric system are connected together by means of a circuit breaker, a coil for con-V trolling the closing of the circuit breaker, a circuit for said coil connected across one of said sections, another circuit for said coil connected across the other of said sections, contacts connected so that the closing there of completes only one of said circuits, a relay rcsponsive to the voltage across one of said sections for effecting the closing of said contacts when the voltage impressed on said relay exceeds a predetermined value, current, limiting means in one of said coil circuits connected so as to be in series between said sect-ions when both of said circuits are completed at the same time, and switching means arranged to be operated to effect the opening of the circuit controlled b said relay when'the other circuit is comp eted.

12. In an automatic reclosing circuit breaker system in which two sections of an electric system are connected together by means of a circuit breaker, a coil for controlling the closing of'the' circuit breaker, a circuit for said coil connected across one of said sections, another circuit for said coil connected across'the other one or said sec tions, contacts connected so that the closing thereof completes only one oi? said coil circuits, a relay responsive to the voltage across one of said sections for efiecting the closing of said contacts, current limiting means in one of said circuits connected so as to be in series between said sections when both of said circuits are completed at the same time, and means controled bysaid relay for preventing the completion of the other coil circuit after said relay hasefiected the completion of above a predeterminedvalue, a second relay responsive to the voltage across the other section for completing the other circuit across said other section to efiect the energization of said coil from said other section when the voltageacross said other section is above a' predetermined value, and current limiting means in one of said circuits arranged so as to be connected in series between said sections only when both of said circuits are simultaneously completed.

14. In an automatic reclosing circuit breaker system in which two sections of an electric system are connected together by means of a circuit breaker, a coil for controlling the closing of the circuit breaker, two circuits for said coil, one of said circuits being across one of said sections so that said one of said circuits is energized by the voltage across said one of said sections, a relay responsive to the voltage across the other section for connectin 'the other circuit of said coil across said ot er section to effect the energization of said coil from said other section when the voltage across said other section is above a predetermined value and current limiting means in one of said coil circuits arranged so as to be connected in series between said sections only when both of said circuits are simultaneously completed.

In witness whereof, I have hereunto set my hand this 2nd day of October, 1923.

ARVID E, ANDERSON.

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